Developing device for an image forming apparatus having a large number of microfields formed on a developer carrier
US5220383A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 1, 1992 |
| Grant date | Jun 15, 1993 |
| Priority date | — |
| Expiry date | Apr 1, 2012 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03G15/0806
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A developing device incorporated in an image forming apparatus and including a developing roller or similar developer carrier for transporting a developer to a developing region where it faces an image carrier, so as to develop a latent image electrostatically formed on the image carrier. The developer carrier has a first and a second substance different in charging characteristic from each other and exposed to the outside on the surface of the developer carrier in a regular or irregular pattern. At least one of the first and second substances is charged to predetermined polarity on the surface of the developer carrier to form a great number of microfields. Alternatively, the developer carrier may have a conductive base and a surface layer provided on the base and constituted by a conductive substance in which insulating particles are dispersed. At least the insulating particles are charged on the surface of the developer carrier to form a number of microfields. The movement of the developer is controlled by an electric field determined by a relation of a potential deposited on the image carrier, an electric field ascribable to the bias applied from a bias applying source, and an e…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.